Wrist pin



J. J. KREJCI.

WRIST PIN FILED NOV-4.1921- Jan. 9, 1923.

FIB.1

mrmv'mze; JOHN J; KR'EJ CI all JUHN J. KREJCI, 0F CQLUIVIBUS, OHIO.

WRIST PIN.

Application filed l Tovember l,

To all 207mm iii 12mg concern:

Be it known that I, -lOHE-T J. liliimoi, u citizen of the United Statesoil. America residing at Columbus, in the county of Fran. lin and Stateof @hio, have invented C'Gll'b new and useful Improvements in lVi-istPins, 01" which the following is a specification.

My present invention relates generally to the cylinders and pistons ofinternal coinhustion engines, air compressors pumps, riv eters, and infact all machinerywherein a cylinder, a piston and a connectingrod orthe piston are parts and more especially my invention relates to themeans of attaching the connecting rods with the pistons.

This is accomplish d at present by wrist pins having square ends whichon endwise displacement are in great source of dangenr in so far asscoring of the cylinder walls is concerned and my invention has for itsohject an improved form of wrist pin which in the event of endwisedisplacement will avoid injury to the cylinder wall along; which thepiston works.

in carrying out my invention I propose a twist pin which will avoidinternal scoring of cylinders through both the shape and character otthe pin as I will hereinafter de scribe with respect to theakcoinpanyine; drawing "forming a part oi this specifics Horn andwherein-- Figure l is side View illustrating the mu-tics] use of theinvention Figure 2 is a plan View oi the waist as proposed by myinvention,

.l i o'ure 3 is a partial longitudinal section therethrough, and

Figure l: is a sectional plan view illustrating: the usual form of wristpin.

Referring now to these figures and particularly to Figures 1 and 4;, awrist pin it) is the ordinary means of connection between a connecting"rod 11 and a piston 12 the latter of which is adapted to work in acylinpin 1921. Serial No; 512,351.

der 8, the wrist pin ordinarily being srguarely cut at its ends asindicatedat in t ig'ure 41'; so that in the event of lengthwisedisplacement of the wrist pin caused by wear, these square e*-ds aresources of DOSsihle and in fact probable internal sc oring' or" thecylinder 13 as indicates 13 in l in' ure i,

in order to avoid this disadvantage and objection I propose a wrist pin15 whose opposite ends areforined with cont-e2; end faces 1e, curred inthe saniedegree as the cylinder walhthat is on a radius the as that or"the cylinder wall. This curvature iscarried in all directions so thatrotation of the wrist pin has no adverse effect upon the eftfciency ofthe construction.

moreover propose that the said ends 16 of the wrist pin he softened inorder to oilset the danger of scoring by either annealinz the ends ofthe wrist-pin or attachingto the ends as by means of welding or otherw'c curved disks .5 or sections of a softer material than that of whichthe wrist pin is formed. This is plainly to be seen at 1'? in .I ure 3.and, the invention thus outlined will he found highly efficient in heprevention of cylinder scoring by endw m C" dacement of the wrist pinswhich so men occurs during wear of the parts.

I claim:

. for cylindi-n tr-r, pistons having soitened end. to avoid l iiu oi? acylinder upon endwise displace-amenior the wrist pin.

2. wrist pin for cylinder traversing pistons. hating softened ends toavoid cylin .l scoiino upon endwise displacement of tile pin in use,said to conform to the curmture oi a Wall. s

in testimony whereof I have afiixed my signature.

cyliiuler JOHN J. KREJCL softened ends being curved i

